1. Field of the Invention
This invention relates generally to electric control devices and more particularly to contactors and relays that are operated by electromagnetic operating means and use auxiliary contacts for interlocking functions in electric control schemes.
2. Description of the Prior Art
In the art of electric control, designers have continuously sought control devices that are both reliable and efficient. Electric control devices have been provided that utilize auxiliary contact combinations for separate interlocking functions in numerous variations. Traditionally, these auxiliary contact devices have been actuated by an actuating member connected to the electromagnetic operating means responsible for opening and closing the electric circuit. The actuating member is disposed to move a contact-carrying structure of the auxiliary contact device to operate the auxiliary contacts as the electric control device goes from one operating position to another. When the auxiliary contact device is released by the actuating member the auxiliary contact device is spring biased to return to its normal position. The biasing means utilized in auxiliary contact combinations has created problems in some control applications because the operating means must perform additional work against the biasing to close the primary contacts, thus requiring larger electromagnetic coils. This biasing also increases the possibility of premature dropout of the coil under low operating voltage conditions.